1. Technical Field
The present invention relates to inclination detection methods and inclination detection apparatuses.
2. Related Art
In general, detection of the movement state of a body is often performed by attaching an acceleration sensor or an angular velocity sensor (a gyroscope) to the body. Objects for which such a sensor is used include a wide variety of objects, such as automobiles, planes, ships, and industrial robots. When the sensor is used for such an object, the accuracy of the sensor is important, and power consumption is of secondary concern. However, when the movement of an inclined surface, for example, is measured, how much the sensor itself consumes power is sometimes more important than the accuracy of the sensor due to the difficulty of supplying required power depending on the location in which the sensor is placed.
As a low-power consumption sensor, an inclination sensor using a spherical electric conductor is known. When such an inclination sensor is used, although a specific state can be detected, the accuracy of measurement of a subtle state change is lower than that of the commonly-used acceleration sensor and angular velocity sensor. Therefore, the inclination sensor is sometimes used for applications which do not require too much accuracy and when it is necessary to reduce power consumption.
As an example of an inclination sensor, JP-A-5-118842 (Patent Document 1), for example, proposes a directional sensor apparatus which provides a plurality of depressions having electrodes on the inner periphery of a ring-shaped frame and detects the direction of rotation (direction of inclination) based on in which depression of the plurality of depressions an electric conductor moving the inside of the ring-shaped frame is located.
Moreover, JP-A-10-319130 (Patent Document 2) proposes a seismometer which is used for calculating an earthquake intensity by accumulating the ON time of the ON/OFF pulse time generated by the vibration of a movable electric conductor.
However, the directional sensor apparatus of Patent Document 1 has a problem in the difficulty of forming a plurality of depressions having electrodes on the inner periphery of a ring-shaped frame. In addition, the seismometer of Patent Document 2 has a problem in the difficulty of reducing power consumption because the load on an arithmetic processing section (a CPU, a memory, a determination program, etc.) for determining an earthquake intensity based on an ON pulse train coming from the movable electric conductor. If an inclination sensor (an inclination detection apparatus) with accuracy that allows the inclination sensor to be used as an alternative to the common acceleration sensor and angular velocity sensor, there is a possibility that the inclination sensor will be used for wider applications.